/* 
    传入坐标，获取图幅号
*/
export function meshByLoc(loc) {
    var rr = parseInt(loc[1] / 4);
    var ll = parseInt (loc[0] / 6);

    var map_row = rr + 1;
    var map_col = ll + 31;
    var c_map_row = String.fromCharCode(65 + map_row - 1);
    var row = (48 - parseInt ((loc[1] - rr * 4) * 12))+'';
    var col = (parseInt ((loc[0] - ll * 6) * 8) + 1)+'';

    var mesh = c_map_row+'';
    mesh = mesh + map_col + 'F';
    if(row.length < 3){
        var len = 3-row.length;
        for(var i=0;i<len;i++){
            row = 0+row;
        }
    }
    mesh = mesh +row;
    if(col.length < 3){
        var len = 3-col.length;
        for(var i=0;i<len;i++){
            col = 0+col;
        }
    }
    mesh = mesh +col;
    return mesh;
}
